Reflectance Spectra of Thermochromic Asphalt Binder: Characterization and Optical Mixing Model
Publication: Journal of Materials in Civil Engineering
Volume 28, Issue 2
Abstract
Asphalt pavement constructed with traditional asphalt binder, which features high solar absorbance, is characterized by high surface temperatures during summer. This causes undesirable performance degradation (i.e., due to accelerated rutting, bleeding, etc.) and environmental consequences (i.e., urban heat island effects and volatile gas emission). Thermochromic asphalt binder, which is asphalt binder mixed with thermochromic materials, has been developed by the authors to dynamically control the solar reflectance and modulate the surface temperature of asphalt pavement. The goal is to improve its long-term durability and environmental friendliness. Thermochromic materials are substances that can reversibly change their colors in response to temperature. The binary thermochromic asphalt binder mixture is produced by incorporating thermochromic powders into a conventional asphalt binder. Measurements of spectral reflectance of thermochromic powders indicate that thermochromic materials feature higher solar reflectance at higher temperatures. In this paper, the spectral reflectance of thermochromic powders as functions of wavelength and temperature are fitted with common types of optical mixing models based on experimental data. Optical measurements conducted on the thermochromic asphalt binder mixture show that they feature more solar reflectance than conventional asphalt binders; furthermore, reflectance increases with temperature. The spectral reflectance of thermochromic asphalt binder also increases as the powder content increases. The common types of optical mixing formulas, including those based on Maxwell, Mori-Tanaka, and effective medium theory (EMT), etc., are used to establish the relationship between spectral reflectance of thermochromic asphalt binder and powder content. These optical mixing formulas provide a convenient way to predict the reflectance spectra of thermochromic asphalt binder and will assist its multifunctional design and optimization.
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Acknowledgments
This study is supported by the Ohio Department of Transportation via the Ohio Partnered Research Exploration Program in partnership with the Ohio Flexible Pavement Association. Technical liaisons from ODOT include David Powers, Roger Green, Lloyd Welker, and Adam Au. The support and assistance from these organizations and individuals are highly appreciated.
References
ASTM. (2012). “Standard test method for solar absorptance, reflectance, and transmittance of materials using integrating spheres.” E903–12, West Conshohoken, PA.
Bottcher, C. J. F. (1952). Theory of electric polarization, Elsevier, New York.
Davis, H. T., Valencourt, L. R., and Johnson, C. E. (1975). “Transport processes in composite media.” J. Am. Ceram. Soc., 58(9–10), 446–452.
Doulos, L., Santamouris, M., and Livada, I. (2004). “Passive cooling of outdoor urban spaces. The role of materials.” Sol. Energy, 77(2), 231–249.
Hao, P. W., Zhang, D. L., and Hu, X. N. (2000). “Evaluation method for low temperature anticracking performance of asphalt mixture.” J. Xi’an Highway Univ., 20(3), 1–5.
Hashin, Z. (1968). “Assessment of the self-consistent scheme approximation: Conductivity of particulate composites.” J. Compos. Mater., 2(3), 284–300.
Hu, J. Y., and Yu, X. (2013a). “Experimental study of sustainable asphalt binder: Influence of thermochromic materials.”, Transportation Research Board, Washington, DC, 108–115.
Hu, J. Y., and Yu, X. (2013b). “Innovative chromogenic materials for pavement life extension: Modeling study of surface temperature of sustainable asphalt pavement.” Int. J. Pavement Eng., 6(2), 141–146.
Kanerva, H. K., Vinson, T. S., and Zeng, H. (1994). “Low temperature cracking field validation of the thermal stress rest rained specimen test.”, Strategic Highway Research Program, National Research Council, Washington, DC.
Kinouchi, T., Yoshinaka, T., Fukae, N., and Kanda, M. (2004). “Development of cool pavement with dark colored high albedo coating.” 5th Conf. for the Urban Environment, American Meteorological Society, Washington, DC.
Landauer, R. (1952). “Electrical transport and optical properties of inhomogeneous media.” J. Appl. Phys., 23(7), 779–784.
Ma, Y. P., and Zhu, B. R. (2009). “Research on the preparation of reversibly thermochromic cement based materials at normal temperature.” Cem. Concr. Res., 39(2), 90–94.
Matlab [Computer software]. Natick, MA, Mathworks.
Maxwell, J. C. (1904). A treatise on electricity and magnetism, Oxford University Press, Cambridge, U.K.
Mori, T., and Tanaka, K. (1973). “Average stress in matrix and average elastic energy of materials with misfitting inclusions.” Acta Mater., 21(5), 571–574.
Pomerantz, M., and Akbari, H. (1998). “Cooler paving materials for heat island mitigation.” Proc., 1998 ACEEE Summer Study on Energy Efficiency in Buildings, American Council for Energy Efficient Economy, Washington, DC.
Pomerantz, M., Akbari, H., Chen, A., Taha, H., and Rosenfeld, A. (1997). “Paving materials for heat island mitigation.”, Lawrence Berkeley National Laboratory, Berkeley, CA.
Pomerantz, M., Akbari, H., and Harvey, J. T. (2000). “Cooler reflective pavements give benefits beyond energy savings: Durability and illumination.”, Lawrence Berkeley National Laboratory, Berkeley, CA.
Saeli, M., Piccirillo, C., Parkin, I. P., Binions, R., and Ridley, I. (2010). “Energy modelling studies of thermochromic glazing.” Energy Build., 42(10), 1666–1673.
Santamouris, M., Pavlou, K., Synnefa, A., Niachou, K., and Kolokotsa, D. (2007). “Recent progress on passive cooling techniques: Advanced technological developments to improve survivability levels in low-income households.” Energy Build., 39(7), 859–866.
Santamouris, M., Synnefa, A., Kolokotsa, D., Dimitriou, V., and Apostolakis, K. (2008). “Passive cooling of the built environment—Use of innovative reflective materials to fight heat island and decrease cooling needs.” Int. J. Low Carbon Technol., 3(2), 71–82.
Synnefa, A., Dandou, A., Santamouris, M., Tombrou, M., and Soulakellis, N. (2008). “Large scale albedo changes using cool materials to mitigate heat island in Athens.” J. Appl. Meteorol. Clim., 47(11), 2846–2856.
Yoder, E. J., and Witzak, M. W. (1975). Principles of pavement design, Wiley, New York.
Zimmerman, R. W. (1989). “Thermal conductivity of fluid-saturated rocks.” J. Pet. Sci. Eng., 3(3), 219–227.
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Published In
Journal of Materials in Civil Engineering
Volume 28 • Issue 2 • February 2016
Copyright
© 2015 American Society of Civil Engineers.
History
Received: Jul 21, 2014
Accepted: May 21, 2015
Published online: Aug 7, 2015
Discussion open until: Jan 7, 2016
Published in print: Feb 1, 2016
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